Open-hearth furnace



A. T. KELLER OPEN HEARTH FURNACE March lZl, 1 925.

2 Sheets-Sheet l Filed Deo. 5, 1921 lgina 'March 24, 1925, A. T. KELLER OPENHEARTMH FURNACE Original Filed Deo. 5, 1921 2 Sheets-Sheet t Patented Mar. 24, 1925.

UNlTED STATES PATENT OFFECE.

ALBERT 'I'. KELLER, OF BETHLEHEM, PENNSYLVANIA, ASSIGNOR TO BETHLEHEM.'

STEEL COMPANY, OF BETHLEHEM, PENNSYLVANIA, A CORPORATION OF FENN- SYLVANIA.

OPEN-HEARTH FRNACE.

Application filed December 5, 1921, Serial No. 520,043.

To @ZZ 107mm it may concern Be it known that I, ALBERT T. KELLER, a citizen of the United States, and residing at Bethlehem, Northampton County, State of Pennsylvania, have invented certain new and useful Improvements in @pen-Hearth Furnaces, of which the following is a specilication.

rEhe present invention relates to regenerative furnaces and particularly to reversible reverberatory regenerative furnaces of the type used in the manufacture of steel by the open hearth process.

The object of the invention is to provide a furnace having a novel and improved end construction permitting the combustible mixture to be supplied at relatively high velocity thereby enabling the furnace output or rate of production to be materially increased and without shortening the effective length of its life.

The invention may be embodied in various forms, one of which is illustrated in the accompanying drawings, in which:

Figure 1 is a vertical longitudinal central section through one end of the furnace;

Figure 2 is a section on line 2-2 of Figure 1;

Figure 3 is a section on line 3 3 of Figure 1;

Figure 1 is a view similar to Figure 1 but sliowing one of the parts in a different position;

*igure 5 is similar to Figure 2 but showing one part in diiferent adjustment; and

Figure G is a section on line 6 6 of Figure 5.

The furnace is preferably formed with its end portions of similar design and construction, and it is therefore necessary for prescnt purposes to illustrate and describe one end of the furnace only. The hearth is indicated at 1() and reverberatory roof at 11, the hearth bein@ provided with the upwardly and outwardly inclined end portions 10', the roof being provided with the downwardly and outwardly inclined portion 11, these portions converging toward the throat 12 through which the gas and air are introduced into the combustion chamber and through which the products of combustion lake their escape whenthe furnace is reversed. Beyond the throat the roof slopes upwardly and outwardly While the floor is Renewed January 15, 1925.

substantially horizontal. Air and gas uptalres are indicated at 13 and 14 respectively, these channels communicating at their lower end with flues 15 and 16 respectively, leading to regenerating chambers. The channels 13 terminate in ports 17 and the channel 14 turns toward the throat 12 and terminates in a gas outlet port 18.

The throat 12 is of less width than the combustion chamber, the furnace walls having the reentrant portions 19, the rear inner surfaces 19 of these reentrant portions serving to deflect air which issues from the ports 17 toward the center of the furnace and against the stream of gas issuing from port 18. rThe portions 19 of the side walls and also the roof and floor of the furnace are slotted to receive the rotatable damper 20. This damper, which may be vertically disposed but which is preferably rearwardly inclined, has a peripheral metal ring 21 provided with teeth 22 which mesh with the teeth of a gear 23 rotatably mounted on a bracket 23 secured to the furnace wall and which gear meshes in turn with a pinion 24; on the motor shaft 25 of a motor 111. Rotation of the motor upon the closing of a switch causes the rotation of the damper 20, which is-supported upon rollers 2G and is guided between stationary plates or rings 27 and 28. Rollers 26 are supported at the ends of members 29 which in turn are pivotally mounted on pedestals 30. Supporting the damper in this manner permits itto be freely rotated while at the same time possible changes in its shape, due to the intense heat to which it is subjected, cannot interfere with its movements. As can be seen from Figures 1 and 3, the throat 12 is elongated in cross section and, as illustrated in Figures 2 and 5, the damper 2O is provided with an opening 20 of substantially similar shape, although somewhat smaller. By rotating the damper therefore this opening may be brought either into full register with the throat, as shown in Figure 2, or only into partial register, as shown in Figure 5.

When the end of the furnace illustrated is serving as the inlet end the damper is arranged as shown in Figure 5, with the long axis of the opening 20 vertically disposed. The combustible gas from the port 18 1s free to pass through opening 20 which lies immediately in front, but only a limited port area is available for the passage of air into the combustion chamber. l'llhen, however, this end of the furnace is the outlet end the damper is arranged so that the long axis of opening 20 is horizontal, as shown in Figure 2, so that a. maximum opening through the throat is pimitled for the escape of products of combustion and the corrosive action of the hot gases on the gas port practically eliminated, even When the air or conibustible gas, or both, introduced at the opposite end of the furnace are supplied un der pressure and the gases are passing at relatively high speed through the comenstion chamber. lf desired, the damper may be arranged with the opening 20 disposed in positions other than horizontal or verti` calthat is, in intermediate positions, to vary the ioiv of the incoming gas and air.

The damper 2O is preferaoly rearwardly or downwardly7 inclined so that the rear face of ring 2l rests against plate 2T thereby preventing the escape of hot gas and air between the ring 2l and this plate at the inlet end. A slight amount of air may be drawn into the throat through the joint between the damper and plate 28, at the inlet end, but not enough to effect the Working of the furnace. rlhe inclination of the damper may be otherwise varied if desired and the invention may be embodied in different types and designs of furnaces, not being` limited to the specific structure shown and described.

Having thus described the invention What I claim as new and desire to secure by Letters Patent is:

l. An end construction for regenerative furnaces, iaving a throat and a single dann per which may be adjusted to throttle the throat opening from opposite sides.

2. An end construction for regenerzfitive open hearth furnaces, having a throat of noncircular cross section, and a damper having an opening therein of substantially similar shape, said damper being rotatable to bring the opening` therein wholly or in partinto register with the throat, as desir-ed.

3. An end construction for regenerative open hearth furnaces having a gas port positioned centrally and opening into a throat leading to the combustion chamber, channels for conducting' air to the throat adjacent the gas port, and a single damper in the throat for throttling thefloiv of air ou both sides of the gas port.

4. An end construction for regenerative open hearth furnaces having a gas port positioned centrally and opening into a throat leading to the combustion chamber, channels for conducting air to the throat adjacent the gas port, and a single damper in the throat which is adjustable to throttle the flow of air through the throat Without obstructing the flow of gas.

5. An end construction for regenerative open hearth furnaces having` a gas port positioned centrally and opening into a throat leading to the combustion chamber, channels for conducting air to the throat adjacent the gas port, and a flat transversely arranged rotatable damper With an elongated central aperture, for throttling the llow of air through the throat Without obstructing the flow of gas.

6. An end construction for regenerative pen hearth furnaces haring` a throat 'with non-circular cross section, and a disk-shaped damper mounted on rollers and haifing an opening therein substantially similar in outline to the throat-section, said damper being rotatable to bring the damper opening either Wholly or in part into register with the throat.

In testimony whereof I hereunto aiiix my signature.

ALBERT T. KELLER.

CIA

Cil 

